The invention is based on a drill- and/or chipping hammer.
Drill- and/or chipping hammers with pneumatic beater mechanisms are known that can be activated and deactivated via a mechanical friction coupling. If the drill- and/or chipping hammer is pressed with a tool against a machining surface, a tool holder that holds the tool is guided, in the direction of a user, into a housing of the drill- and/or chipping hammer. In the process, conical friction faces of the friction coupling come into contact, and the pneumatic beater mechanism is driven via a nonpositive engagement. During operation, with an axially movable piston guided in a cylinder, the beater mechanism generates a cushion of compressed air, which accelerates a beater in the axial direction against an impact bolt. The beater strikes the impact bolt, which thereby experiences a pulse.
If the drill- and/or chipping hammer with the tool is lifted from the machining surface, the frictional faces of the friction coupling are disconnected by a so-called idling spring, and the drive connection of the beater mechanism is broken.